{"id":{"repo_id":"heid-diss","oai_identifier":"oai:archiv.ub.uni-heidelberg.de:5618"},"canonical_url":"https://search.dev.ndltd.org/etd/heid-diss/oai:archiv.ub.uni-heidelberg.de:5618","repository":{"repo_id":"heid-diss","name":"Universität Heidelberg","base_url":"http://archiv.ub.uni-heidelberg.de/volltextserver/cgi/oai2"},"display":{"title":"Investigation of Exclusive Photoproduction of eta-rho0 and pi0-rho0 Meson Pairs at HERA","abstract":"Exclusive photoproduction of $\\eta-\\rho^{0}$ and $\\pin-\\rho^{0}$ meson pairs is studied with the H1 detector at HERA. The analysis is based on data recorded in 1996-1997 and 1999-2000 data taking periods, corresponding to an integrated luminosity of $76.21\\,\\,{\\tt pb}^{-1}$. %{/pb}$. The $\\eta$ and $\\pin$ mesons are identified via their photonic decays in the backward calorimeter SpaCal, and the $\\rho^{0}$ meson via its dominant decay into $\\pip\\pim$ pairs in the central tracking system of the H1 detector. The scattered proton or its remnant is not measured but is separated by a large rapidity gap from the $\\rho^{0}$ meson. \\\\ The cross section for photoproduction of $\\eta-\\rho^{0}$ meson pairs is measured at an average photon-proton center of mass energy of $W\\approx208\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\eta$ and $\\rho^{0}$ mesons in the laboratory system: $-3.5<Y^{lab}_{\\eta}<-2$ and $-1.5<Y^{lab}_{\\rho^{0}}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$ and inelasticity $0.3<y<0.65$. The cross section obtained is $\\sigma^{*}(\\gamma p\\rightarrow\\eta\\rho^{0} X) = (3.5 \\pm 1.4 (stat) \\pm 1.3 (syst))\\,\\,\\, {\\tt nb}$. Due to the limited statistics no definitive statement is made to explain this process but the measured differential distributions are consistent with a contribution from Pomeron exchange.\\\\ In the analysis of photoproduced $\\pin-\\rho^{0}$ meson pairs no significant $\\rho$ meson signal can be extracted. % the signal of the $\\rho^{0}$ meson can not exctracted. Therefore only an upper limit of the cross section is given as $\\sigma^{*}(\\gp\\to\\pin \\, \\rho^{0} \\, X) \\, < \\, 8.6 \\,\\,\\,{\\tt nb}$ at $95\\,\\%$ confidence level, measured at an average photon-proton center of mass energy of $W\\approx180\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\pin$ meson and the $\\pip\\pim$ pair in the laboratory system: $-3.5<Y^{lab}_{\\pin}<-2$ and $-1.5<Y^{lab}_{\\pim\\pip}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$, and inelasticity $0.3<y<0.65$.","abstract_html":"Exclusive photoproduction of <span class=\"etd-inline-math\">\\eta-\\rho<sup>0</sup></span> and <span class=\"etd-inline-math\">&pi;n-\\rho<sup>0</sup></span> meson pairs is studied with the H1 detector at HERA. The analysis is based on data recorded in 1996-1997 and 1999-2000 data taking periods, corresponding to an integrated luminosity of <span class=\"etd-inline-math\">76.21  {\\tt pb}<sup>-1</sup></span>. %{/pb}$. The $\\eta$ and $\\pin$ mesons are identified via their photonic decays in the backward calorimeter SpaCal, and the $\\rho^{0}$ meson via its dominant decay into $\\pip\\pim$ pairs in the central tracking system of the H1 detector. The scattered proton or its remnant is not measured but is separated by a large rapidity gap from the $\\rho^{0}<span class=\"etd-inline-math\"> meson. \\ The cross section for photoproduction of </span>\\eta-\\rho^{0}$ meson pairs is measured at an average photon-proton center of mass energy of $W\\approx208\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\eta$ and $\\rho^{0}$ mesons in the laboratory system: $-3.5&lt;Y^{lab}_{\\eta}&lt;-2$ and $-1.5&lt;Y^{lab}_{\\rho^{0}}&lt;1.5$, photon virtualities $Q^{2}&lt;0.01\\,{\\tt GeV}^{2}$ and inelasticity $0.3&lt;y&lt;0.65$. The cross section obtained is $\\sigma^{*}(\\gamma p\\rightarrow\\eta\\rho^{0} X) = (3.5 \\pm 1.4 (stat) \\pm 1.3 (syst))\\,\\,\\, {\\tt nb}<span class=\"etd-inline-math\">. Due to the limited statistics no definitive statement is made to explain this process but the measured differential distributions are consistent with a contribution from Pomeron exchange.\\ In the analysis of photoproduced </span>\\pin-\\rho^{0}$ meson pairs no significant $\\rho$ meson signal can be extracted. % the signal of the $\\rho^{0}$ meson can not exctracted. Therefore only an upper limit of the cross section is given as $\\sigma^{*}(\\gp\\to\\pin \\, \\rho^{0} \\, X) \\, &lt; \\, 8.6 \\,\\,\\,{\\tt nb}$ at $95\\,\\%$ confidence level, measured at an average photon-proton center of mass energy of $W\\approx180\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\pin$ meson and the $\\pip\\pim$ pair in the laboratory system: $-3.5&lt;Y^{lab}_{\\pin}&lt;-2$ and $-1.5&lt;Y^{lab}_{\\pim\\pip}&lt;1.5$, photon virtualities $Q^{2}&lt;0.01\\,{\\tt GeV}^{2}$, and inelasticity $0.3&lt;y&lt;0.65$.","abstract_has_math":true,"creators":["Tomasz, Filip"],"institution":"Universität Heidelberg","degree_name":null,"degree_level":"thesis.doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Meier, Karlheinz,"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005-06-29","date_published":"2005-06-29","updated_at":"2026-07-24T02:30:12Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://www.ub.uni-heidelberg.de/archiv/5618","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Meier, Karlheinz,"]},{"key":"dc:creator","label":"Author","values":["Tomasz, Filip"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["Universitätsbibliothek Heidelberg"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]},{"key":"thesis:degree_level","label":"Degree Level","values":["thesis.doctoral"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Universität Heidelberg"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Exclusive photoproduction of $\\eta-\\rho^{0}$ and $\\pin-\\rho^{0}$ meson pairs is studied with the H1 detector at HERA. The analysis is based on data recorded in 1996-1997 and 1999-2000 data taking periods, corresponding to an integrated luminosity of $76.21\\,\\,{\\tt pb}^{-1}$. %{/pb}$. The $\\eta$ and $\\pin$ mesons are identified via their photonic decays in the backward calorimeter SpaCal, and the $\\rho^{0}$ meson via its dominant decay into $\\pip\\pim$ pairs in the central tracking system of the H1 detector. The scattered proton or its remnant is not measured but is separated by a large rapidity gap from the $\\rho^{0}$ meson. \\\\ The cross section for photoproduction of $\\eta-\\rho^{0}$ meson pairs is measured at an average photon-proton center of mass energy of $W\\approx208\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\eta$ and $\\rho^{0}$ mesons in the laboratory system: $-3.5<Y^{lab}_{\\eta}<-2$ and $-1.5<Y^{lab}_{\\rho^{0}}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$ and inelasticity $0.3<y<0.65$. The cross section obtained is $\\sigma^{*}(\\gamma p\\rightarrow\\eta\\rho^{0} X) = (3.5 \\pm 1.4 (stat) \\pm 1.3 (syst))\\,\\,\\, {\\tt nb}$. Due to the limited statistics no definitive statement is made to explain this process but the measured differential distributions are consistent with a contribution from Pomeron exchange.\\\\ In the analysis of photoproduced $\\pin-\\rho^{0}$ meson pairs no significant $\\rho$ meson signal can be extracted. % the signal of the $\\rho^{0}$ meson can not exctracted. Therefore only an upper limit of the cross section is given as $\\sigma^{*}(\\gp\\to\\pin \\, \\rho^{0} \\, X) \\, < \\, 8.6 \\,\\,\\,{\\tt nb}$ at $95\\,\\%$ confidence level, measured at an average photon-proton center of mass energy of $W\\approx180\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\pin$ meson and the $\\pip\\pim$ pair in the laboratory system: $-3.5<Y^{lab}_{\\pin}<-2$ and $-1.5<Y^{lab}_{\\pim\\pip}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$, and inelasticity $0.3<y<0.65$."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Investigation of Exclusive Photoproduction of eta-rho0 and pi0-rho0 Meson Pairs at HERA","Untersuchung der exklusiven Photoproduktion von eta-rho0 und pi0-rho0 Mesonpaaren bei HERA"]}]}],"canonical_facts":{"dc:contributor":["Meier, Karlheinz,"],"dc:creator":["Tomasz, Filip"],"dc:description.abstract":["Exclusive photoproduction of $\\eta-\\rho^{0}$ and $\\pin-\\rho^{0}$ meson pairs is studied with the H1 detector at HERA. The analysis is based on data recorded in 1996-1997 and 1999-2000 data taking periods, corresponding to an integrated luminosity of $76.21\\,\\,{\\tt pb}^{-1}$. %{/pb}$. The $\\eta$ and $\\pin$ mesons are identified via their photonic decays in the backward calorimeter SpaCal, and the $\\rho^{0}$ meson via its dominant decay into $\\pip\\pim$ pairs in the central tracking system of the H1 detector. The scattered proton or its remnant is not measured but is separated by a large rapidity gap from the $\\rho^{0}$ meson. \\\\ The cross section for photoproduction of $\\eta-\\rho^{0}$ meson pairs is measured at an average photon-proton center of mass energy of $W\\approx208\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\eta$ and $\\rho^{0}$ mesons in the laboratory system: $-3.5<Y^{lab}_{\\eta}<-2$ and $-1.5<Y^{lab}_{\\rho^{0}}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$ and inelasticity $0.3<y<0.65$. The cross section obtained is $\\sigma^{*}(\\gamma p\\rightarrow\\eta\\rho^{0} X) = (3.5 \\pm 1.4 (stat) \\pm 1.3 (syst))\\,\\,\\, {\\tt nb}$. Due to the limited statistics no definitive statement is made to explain this process but the measured differential distributions are consistent with a contribution from Pomeron exchange.\\\\ In the analysis of photoproduced $\\pin-\\rho^{0}$ meson pairs no significant $\\rho$ meson signal can be extracted. % the signal of the $\\rho^{0}$ meson can not exctracted. Therefore only an upper limit of the cross section is given as $\\sigma^{*}(\\gp\\to\\pin \\, \\rho^{0} \\, X) \\, < \\, 8.6 \\,\\,\\,{\\tt nb}$ at $95\\,\\%$ confidence level, measured at an average photon-proton center of mass energy of $W\\approx180\\,{\\tt GeV}$ in the kinematical region defined by the rapidities of the $\\pin$ meson and the $\\pip\\pim$ pair in the laboratory system: $-3.5<Y^{lab}_{\\pin}<-2$ and $-1.5<Y^{lab}_{\\pim\\pip}<1.5$, photon virtualities $Q^{2}<0.01\\,{\\tt GeV}^{2}$, and inelasticity $0.3<y<0.65$."],"dc:format.medium":["application/pdf"],"dc:publisher":["Universitätsbibliothek Heidelberg"],"dc:title":["Investigation of Exclusive Photoproduction of eta-rho0 and pi0-rho0 Meson Pairs at HERA","Untersuchung der exklusiven Photoproduktion von eta-rho0 und pi0-rho0 Mesonpaaren bei HERA"],"dc:type":["doctoralThesis"],"thesis:degree_level":["thesis.doctoral"],"thesis:institution_name":["Universität Heidelberg"]},"updated_at":"2026-07-24T02:30:12Z"}